A real-time operating system (“RTOS”) is an operating system (“OS”) intended to serve real-time application requests. One beneficial characteristic of an RTOS is the level of its consistency concerning the amount of time it takes to accept and complete an application's task. Furthermore, an RTOS utilizes an advanced algorithm for scheduling. Typically, scheduler flexibility enables a wider, computer-system orchestration of process priorities. However, a real-time OS is more frequently dedicated to a narrow set of applications. Key factors in a real-time OS include minimal interrupt latency and minimal thread switching latency. A real-time OS is valued more for how quickly or how predictably it can respond than for the amount of work it can perform in a given period of time.
Interrupt latency may be described as the time between the generation of an interrupt by a device and the servicing of the device which generated the interrupt. For many operating systems, devices may be serviced as soon as the interrupt handler of the device is executed. Interrupt latency may be affected by interrupt controllers, interrupt masking, and the operating system's interrupt handling methods. Many computer systems require low interrupt latencies, especially embedded systems that need to control machinery in real-time.